If your evaporative cooler produces unpleasant smells when operating, you’re not alone.
Bad odours are one of the most common complaints homeowners experience at the start of summer, particularly when a system has been sitting unused throughout winter.
While some mild smells can occur during startup, persistent odours often indicate that maintenance or repairs are required.
Fortunately, most evaporative cooler smells can be identified and corrected relatively easily.
Why Evaporative Coolers Develop Smells
Unlike refrigerated air conditioning systems, evaporative coolers use water and filter pads as part of the cooling process.
Over time, the combination of water, dust, minerals and organic material can create conditions where unpleasant smells develop.
Common causes include:
- Dirty filter pads
- Stagnant water
- Sludge buildup
- Mould growth
- Algae growth
- Scale accumulation
- Lack of maintenance
The smell often becomes more noticeable when the system is first switched on after a long period of inactivity.
Dirty Filter Pads
One of the most common causes of unpleasant odours is heavily contaminated filter pads.
Over time, pads collect:
- Dust
- Dirt
- Pollen
- Minerals
- Organic debris
As contamination builds up, the pads can develop unpleasant smells that are distributed throughout the home whenever the system operates.
If the pads are heavily soiled or deteriorated, replacement is often the best solution.
Stagnant Water In The Reservoir
Evaporative coolers store water in a reservoir tank.
If water remains inside the system for extended periods, particularly during winter shutdowns, it can become stagnant.
Stagnant water may develop:
- Musty odours
- Mould growth
- Algae growth
- Bacterial contamination
This is one reason why annual startup servicing is recommended before summer begins.
Scale And Sludge Buildup
Perth’s mineral-rich water can create significant scale deposits inside evaporative coolers.
Without regular servicing, scale and sludge can accumulate in:
- Reservoir tanks
- Drain systems
- Water distribution systems
- Filter pads
This buildup can trap organic material and contribute to unpleasant smells.
In severe cases, the inside of the unit may require extensive cleaning before normal operation can resume.
Fishy Smells
Some homeowners describe the smell as fishy rather than musty.
This is particularly common in systems that have experienced years of poor maintenance and heavy scale accumulation.
When mineral deposits, organic material and contaminated filter pads combine, unusual odours can develop and circulate throughout the home.
A thorough cleanout combined with new filter pads often resolves the issue.
Mould And Mildew Growth
If water is not draining correctly or airflow has been restricted, mould and mildew can sometimes develop inside the system.
Signs may include:
- Damp smells
- Musty odours
- Visible mould
- Increased humidity indoors
Mould should be addressed promptly to help maintain healthy indoor air quality.
Can A Service Remove The Smell?
In many cases, yes.
A professional evaporative cooler service typically includes:
- Reservoir cleaning
- Drain flushing
- Filter pad inspection
- Water distribution checks
- Removal of accumulated debris
- General system inspection
Many unpleasant smells disappear once the system has been properly cleaned and serviced.
Where filter pads are heavily contaminated, replacement may also be recommended.
How To Prevent Future Smells
The best way to prevent odours is through regular maintenance.
Annual servicing helps:
- Remove sludge buildup
- Flush stagnant water
- Inspect filter pads
- Maintain drain operation
- Improve water quality inside the unit
Regular maintenance not only improves comfort but can also help extend the life of the evaporative cooler.
Signs Your Cooler Needs Attention
You should arrange an inspection if you notice:
- Musty smells
- Fishy odours
- Mould smells
- Unpleasant air when the system starts
- Reduced cooling performance
- Increased humidity indoors
Ignoring these symptoms can allow the problem to become worse over time.
Book An Evaporative Cooler Service In Perth
If your evaporative cooler smells bad, Air Legends can inspect, clean and service the system to identify the cause and restore performance.
We service and repair all major evaporative cooling brands throughout Perth and can assist with filter pad replacement, reservoir cleaning, scale removal and annual maintenance.
Contact Air Legends today to arrange a professional inspection.